Loud-speaker unit



July 2, 1929. J, M, KING l 1,719,227

LOUD SPEAKER UNIT Filed April l1, 1927 Patented `luly 2,1929. o

UNITED STATES PATENT OFFICE.

JOSEPH M. S. KING, OF SA'LT LAKE CITY, UTAH, ASSIGNOR TO THE UTAH RADIO PRODUCTS COMPANY, OF SALT LAKE CITY, UTAH, A CORPORATION OF UTAH.

Loon-SPEAKER UNIT.

Application .tiled April 11, 1927. Serial No. 182,779.

This invention relates to a loud speaker unit having an oscillating armature, and its principal objects are: A

First. To firmly mount the armature.

Second. To cause the mounting to be substantially permanent, thus giving it maximum durability. A

Third. To have the armature support firmly gripped ina comparatively heavy surrounding structure or mounting member, yet at the same time to give the armature great freedom and delicacy of action.

Fourth. To be free from the liability to rattle in even a slight degree.

Fifth. To simplify the details of the component pieces, and their relative assembly.

Sixth. To facilitate economical manufacture While maintaining a high degree of mechanical perfection.-

In any loud speaker, the heart of the instrumentl is the armature. Therefore, the life and performance of the instrument depend primarily uponthe armature and its mounting, in fact, no loud speaker is any better than its armature mounting.

Essentially, in attaining the objects just i outlined, I carry the armatureon a supporting member, consisting preferably of a plate or disk to which the armature is rigidly connected, for instance, by Welding, or the armature and supporting member may be made substantially integral With each other in any other desired way. The plate, around the bounding edges thereof, is imbedded or other- Wise secured in what may be termed the mounting member. v

When the armature vibrates, the plate is slightlywarped or distorted ateach impulse, and even though the number of these pulsations is infinitely great, the stresses caused thereby, lie far Within the elastic limit of the material of which the armature is made, so that the pulsations may take place indelinitely, Without any appreciably deleterious effects uponthe molecular structure of the said material. Naturally, the plate should'be iexible or resilient.

While fundamentally, the supporting member may be a continuous plate, and may lie .substantially in a plane, many variations in the detailed structure thereof may be made, such as perforating it in various Ways even ber by being imbedded therein when the said material is in a molten state, as would be the case in the instance of a cast metal'.

Instead of a metal, it will .be understood that a plastic substance such as bakelite, may be employed.

The single item of fitting and mounting the armature as ordinarily accomplished by others, involves considerable time and labor,

`and therefore expense, which may easily be saved by theuse of my invention.

' In operation, lthe pounding caused by the extremely rapid rate of its vibration, has a tendency to soon cause the armature in any loud speaker, as heretofore mounted, to become loose in its bearings, and so to introduce a rattle or foreign element. into the sound emitted by any instrument of which the armature may be a part.

In the present invention, not only is this defect overcome, but owing to the inertia ot the heavy mounting member, the tendency of the latter to assume a sympathetic vibration with the armature and its supporting member, is' practically overcome. This is due to the fact that any pounding transmitted from the armature through the supporting member, is absorbed by the mounting member, much after the manner of an anvil, which, due to its lgreater inertia, may be said t0 absorb the force of the blows of al lighter hammer. By making the mounting member of a soft metal or alloy, such as tin, lead Babbitt metalor type metal, having only a sluggish vibratory action, the dampening effect of the mounting member upon undesirable vibratory motion is enhanced.

In order to give briefly a clear idea of my invention, as reduced to practice, ll will de- The plate is supported around its periphery either continuously or at intermittent points, b the mounting member, which is preferably of extremely liberal dimensions, thus giving the mounting member great lnertia 1n comparison with the inertia ot the armature and its supportin member.

The mounting mem er may conveniently be made in the form of a circular ring within which the supporting member is mounted. This ring provides for the compact disposition of an electromagnetic coil on each side of the armature support, and results in economies redecmd in assembly costs, and further, presents a very desirable nesting arrangement of parts..l

By forming the ring around the supporting member, while the material of the Jrormer is in a molten or plastic state, ll secure not only the desired irm grip upon the supporting member, but also accomplish this most useful result at a minimum of expense.

The ring is adapted for mounting between pole pieces of a special design, which latter are mounted on a perectly simple lil-shaped permanent magnet in the loud speaker assemblyo The features of this invention for which the protection ot Letters Patent is desired,

are collectively grouped in the claims concluding this speciiication.

ln the drawing, which for convenience illustrates merely one embodiment ont this invention,

Fig.. 1 represents a plan;

Fig.. 2, a section online 2, Fig. 1;

llig. il, an elevation in the direction ot arrow 3, Fig. 1;

Fig. 4l, a perspective of a pole piece;

Fig. 5, a perspective of the armature and its mounting, part being broken away to show the interior more clearly;

Fig. (i, a fragmentary center section of a modification of the armature mounting;

F ig. 7, a center section through a mold, with the armature and its disk in place therein, ready for the pouring ofthe metal; and

Fig. 8, a View, in perspective, of a spool.

Referring to the drawing, 10 indicates an armature of the bar type, which may be Welded or otherwise secured at 12 to the plate or disk 14 which constitutes the supporting member. Extending around the periphery of the disk 14, is the ring 15 which constitutes the mounting member, and abutting against the disk on opposite sides thereof, are the annular Hanges or abutments 16, extending inwardly from the ring 15.

Nested in the ring 15, on opposite sides of the disk 14, and resting against the abutments 16, are the spools or bobbins 17, upon which are wound the coils 18 of the electromagnet. 'lhe abutments 16 thus act as spacing members for spacing the spools apart from the disk 14: to give the latter the proper freedom for vibrating.

The ring 15 is secured between the legs 191 of the pole pieces 19 by means of the screws 21. The pole pieces 19 are secured to the legs 201 and 202 of the permanent magnet 20, and this assemblage in turn, to the plate 24, by means of the studs 25.

The diaphragm 26 is clamped between the resilient gaskets 27, these being secured bctween the cap 28 and the plate 2d, which are fastened together by the screws 29. @ne end of the armature 10 is connected to the daphragm 26 by means of the usual pin 30.

Should it be desired to make the ring in two parts instead of casting it around the disk, this could be done by inserting the disk 11i between the halves 31 and 32 as shownin Fig. 6.

A mold Fig. `7, for casting the ring 15 around the disk, may consist of the two caps 3d and the interposed body pieces 35. Holes 36 are provided to receive the armature 10. "lhe armature and the disk are shown inserted in the mold ready to have the molten metal poured through gate 37 intothe space 38.

lt will be noted that the anis of oscillation olf the armature, passes substantially through the juncture of the armature with its supporting member, and also, that the longitudinal anis ot the armature passes through this center so that these two axes intersect each other in this point.

The anchorage oi the supporting member in the mounting member, may be said to lie along a circumferential or perimetral margin extending around the longitudinal axis. This margin is composed of an inlinite number of points lying on radii emanating from the longitudinal airis.,

A. definition of the principal parts of this invention as broadly used herein, seems desirable, therefore, it may be well to state that supporting member means the plate or its equivalent; mounting member means the ring or its equivalent; and armature mounting or simply mounting means the supporting member and mounting member together. l

Although the part indicated at 10 is generally known as the armature, it `functions in the capacity of an armature with respect to the magnet 20 only. Considered as a part of the clectromagnet, part 10 functions as a core.

l am aware that oscillating armatures, electromagnet coils, U-shaped or other magnets.. pole pieces and diaphragms have heretofore been used together in loud-speakers manyl dii'erent ways, so l do not claim broad1y,a combination of such elements, but limit my invention to the novel construction of the ldd lid

armature, the armature mounting and the related partsas herein described, and/or to any equivalents of the novelty thereof.

lfVhile a` specific embodiment of this invention is herein shown and described, it is to be clearly understood that all the ydetailed parts thereof, may or may not be shown in the preferred forms, and further, that the preferred forms may be varied from time to time, as the development of this invention and the arts to which it appertains, progress. Therefore, that which forms an essential and characteristic part of this invention, will be readily discernible from the claims in which its spirit is broadly generalized.

Having fully described my invention, what I claim is:

1. In a loud speaker unit, an armature, a flexible member supporting the armature, said flexible member having a perimetral margin, and a mounting member` gripping the said perimetral margin.

2. In a loud speaker unit, an armature, a flexible member supporting the armature, said flexible member having a perimetral margin, and a mounting member cast around the said. flexible member including the said perimetral margin.

3. In a loud speaker unit, an armature, a

flexible member in which said armature is fixed, the said flexible member having a perimetral margin, and a mounting member, formed around the perimeter of the said flexible mem er, said mounting member extending inwardly of the outer rim of said flexible member to include the said perimetral mar- 1n. g 4. In a loud speaker unit, an armature, a flexible supporting member for the armature, said flexible supporting member having a perimetral margin-inside which said armature is rigidly attached to said supporting member; and a mounting member formed around, and gripping, the said perimetral. margin.

5. In a loud speaker unit, an armature having a longitudinal axis, a supporting member intersected by said longitudinal axis, means for rigidly connecting said armature to saidgsupportingmember substantially in proximity te said intersection, a perimetral margin defined on said supporting member, and a mounting member formed around and engaging the said perimetral margin.

6. In a loud speaker unit, an armature having a longitudinal axis, a flexible plate rigidly connected to said armature, transverse to said longitudinal axis, and a mounting member formed around and engaging the perimeter of said plate.

7. An armature having a longitudinal axis, a flexible plate intersecting the armature transverse to said longitudinal axis, said -llexible plate having a perimetral margin; a mounting member formed around the perimeter of the said plate and extending inwardly thereofto4 include said perimetral margin, spools carrying electromagnet coils, said spools nested in said mounting member so as to occupy a transverse area Within said perimetral margin, and pole pieces having arms lying in planes defining end faces of said mounting member and said spools.

8. An armature and armature support, said armature support consisting of a flexible plate in which said armature is rigidly held, said plate having a perimetral mounting margin,4 and a mounting member in which said margin is imbedded.

9. An armature and supporting member, said supporting member consisting of a flexible plate integral with said armature, the surface of said plate substantially transverse to the longitudinal axis of said armature, a perimetral mounting margin enclosing said armature, defined on said plate, and a mounting member in which said margin is imbedded. l

10. An armature having a longitudinal axis and an axis of oscillation intersecting the said longitudinal axis, a plate rigidly connected to said armature at substantially the point of said intersection, said plate having a perimentral margin, and amounting member in which the said perimetral margin is imbedded.

11. In a loud speaker unit, an armature, a

flexible plate supporting the armature, a mounting member disposed around the perimeter of said plate, coils having spools disposed Within said mounting member, and

.means for spacing said spools apart lfrom said flexible plate.

12. In a loud s eaker, an armature having an axis of oscil ation, a supporting member substantially coinciding with said axis of oscillation, and a mounting member formed perimetrally around said supporting member, said mounting member, and said supporting member being substantially integral with each other.

13. An armature and mounting for same, comprising a supporting member in which the armature is rigidly held, said supporting member having a perimetral margin, and a ring formed around the said margin, said margin being imbeded in said ring.

14. In a loud speaker, an armature having an axis of oscillation, a supporting member substantially coinciding with said axis of oscillation, and a mounting member formed perimetrally around said supporting member, the ratio of the mass of the said mounting member to the mass of the said armature and supporting member combined, being large.

15. Aloud speaker comprising an armature having an axis of oscillation, a flexible plate connected to said armature at substantially the center of oscillation, a ring formed around and imbedding the said flexible plate circumferentially, pole pieces having arms lying in planes adjacent the said ring, said planes intersecting the axis of revolution of said ring, and a magnet for energizing the said pole pieces.

16, An armature, a ring-like mounting member, an armature support having a perimetral margin disposed internally of said mounting member transverse thereto, spacing members projecting internall from said mounting member, said spacing members being 'located upon opposite sides of the armature support, and spools bearing against said spacing members.

17. An armature, a disk lixed transversely thereon, and a mounting member substantially enclosing and imbedding the said disk perimetrally.

18. An armature, a disk fixed transversely thereon, a mounting member enclosing said disk, and electromagnetic means disposed Within said mounting member, said electromagnetic means being operative to vibrate said armature.

1n testimony whereof, I sign my name hereto.

JOSEPH M. S. KNG. 

